1. Field of the Invention
The present invention relates to a semiconductor device including a nonvolatile storage element in which a stored logic state (data) is not erased even when supply of power supply voltage is stopped. In particular, the present invention relates to a temporary storage circuit, such as a page buffer, including a nonvolatile storage element; a storage device including the temporary storage circuit; and a signal processing circuit including the storage device. Furthermore, the present invention relates to an electronic device including the storage device or the signal processing circuit.
2. Description of the Related Art
In a memory (storage device) including a page buffer, the page buffer has a function of temporarily holding data for at least one block (for example, a plurality of memory cells electrically connected to one word line) of a memory cell array included in the memory. After data input to the memory is held in the page buffer, the data held in the page buffer is written to one block of the memory cell array. In addition, after data held in one block of the memory cell array is read out and held in the page buffer, the data held in the page buffer is read out. Alternatively, the data held in the page buffer is written again to the one block of the memory cell array. Further alternatively, the data held in the page buffer can be written to another one block of the memory cell array.
A page buffer disclosed in Patent Document 1 includes a plurality of sets. Each set includes a latch circuit, a transistor functioning as a switch that selects the input of data to the latch circuit, and a transistor functioning as a switch that selects the output of data from the latch circuit. The latch circuit includes a flip-flop including two inverters (see FIG. 1 and the like in Patent Document 1).